Domestic and central-heating boiler



Jan. 21, 1947. A. J. WATTS DOMESTIC AND CENTRAL-HEATING BOILER Fil ed Oct. 14, .1944

s Sheets-Sheet 1 WWW M w m ATTORNEYS Jan. 21, 1947. v J WATTS 2,414,782

DOMESTIC AND CENTRAL-HEATING BOILER Filed Oct. 14, 1944 :5 Sheets-Sheet 2 Jan. 21, 1947. A. J. WATTS 2,414,782

- DOMESTIC AND CENTRAL-HEATING BOILER Filedoct 14, 1944 a sheets-sheet 5 MAW:

Arm/ENE Y Patented Jan. 21, 1947 DOMESTIC AND CEN TRAL-HEATIN G BOILER Arthur Josiah Watts, Highfield, Lydney, England Application October 14, 1944, Serial No. 558,767 In Great Britain October 15, 1943 7 Claims.

This invention relates to domestic and centralheating boilers and has for its main object to provide an improved construction of boiler which shall be smaller than those hitherto produced for an equivalent rating and shall have certain additional advantages, such as simplicity of operation, neatness of appearance, automatic fuel feed and so on.

A further object is the provision of means whereby a cooking oven may be combined with the boiler according to the invention so that the one fire may serve two purposes. In addition, means-for utilising an alternative fuel may be provided.

Various proposals have previously been made for adapting existing boilers so that they are continuously supplied with fuel, under the action of gravity, in accordance with the rate at which fuel is consumed in the furnace or firebox, the fuel being stored in a hopper, usually mounted over the top of the boiler, and descending through a pipe to the fire-box where itis supported on a domed or similarly shaped member beneath which air is supplied by a thermostatically-controlled fan. The present invention, however, is concerned with a construction of boiler which embodies all these features in an improved and compact form.

According to the invention a domestic or central-heating boiler comprises a bottom, side and back walls (which may be merged into each other in U- or other shape in plan view) and an upwardly and rearwardly inclined top each of which, with th exception in some cases of the bottom, is formed as a hollow water-filled compartment communicating with each of the other such compartments. The bottom, which in the smaller sizes may be of firebrick or other heatinsulating refractory material, has an aperture through which air maybe supplied and carries above the same a fuel-supporting member which is hollow and connected by water ways either to the water-filled compartments of the boiler proper or to meansfor indirectly heating water or for other purposes. It is preferred to form the said member with an outlet passage through which a proportion of the air supplied beneath the same may pass, being preheated on its way, to means for delivering air above the fuel bed. The inclined top of the boiler forms a seating for a fixed or removable fuel hopper which is correspondingly shaped at the bottom to ensure that the general external appearance of the boiler plus hopper shall be approximately that of a right prism. In order that the capacity of the hopper may be increased as desired, it may have its mouth formed to receive removable extension pieces continuing its walls upwardly. The outlet from the hopper is adapted to register with an aperture formed through .the inclined top of the boilernear the lower end thereof, the Wall of the aperture being continued as a fuel tube or pipe extending to a point above the fuel-supporting member. hopper adjacent to'its outlet so that the latter maybe closed while the hopper is being transported to and from a filling location or during clinkering operations. The outlet from the furnace for combustion'products is preferably arranged near the upper end .of the inclined top of the boiler and delivers to a flue system in contact with the rear wall of the boiler. This flu system may provide an extended path of travel for the hot gases so that the maximum transfer of heat to the boiler wall is achieved and preferably has an opening at one part of its length, normally closed by a cover-plate, over which a cooking oven may be secured so that thehot gases will circulate through fiues therein before returning to the main flue system. In the means for supplying air to beneath the fuel-supporting member may be incorporated a light flap valve which will close automatically when the air is being supplied under pressure but otherwis remains open to permit the natural draught to draw a supply of air through the fire. Furthermore, means is advantageously provided in the air-supply system whereby towns gas may be supplied to beneath the fuel-supporting member so that the boiler may be run for short periods without th use of the normal solid fuel, for example, during summer months. In the larger types of boiler this gas-supplying means may alternatively be employed for admitting Water or steam to the air stream passing to the fire-box.

Certain of the features of the boiler according to the invention are also applicable without modification to pre-heating furnaces in which close control of the temperature is desirable and to industrial plant such as heaters for water or chemicals and drying ovens.

In'order that the invention may be properly understood, an example .of a small domestic water-heating boiler constructed in accordance therewith will now be described with reference to the accompanying somewhat diagrammatic drawings, wherein! Fig. l is a front elevation showing the boiler with a cooking oven combined therewith,

A shut-01f member is provided in the Fig. 2 is a side elevation thereof, mainly in section taken on the line 11-11 of Fig. 1,

Fig. 3 is a section taken on the line IIIIII of Fig, 2, and

Fig. 4 is a fragmentary detail view, in plan, showing the secondary air-supplying means.

In the example illustrated, a small domestic water-heating boiler comprises a combustion chamber i of rectangular shape in plan view but of increasing heightin the rearward direction. It has, accordingly, a fiat rectangular base 2 bounded at its rear edge and its two side edges by vertical walls and a top 3 which inclines upwardly from the front, for example at 45. The base 2 is shown as being lined with firebrick 2a but it may, particularly in larger sizes of boiler, be of hollow construction to provide a waterspace. The rear wall 4, the side walls-5 and 6 and the inclined top 3 are constructed as hollow members the internal spaces of which communicate freely with each other, the return pipe (not shown) of the system supplied from the boiler opening into the lower part of the interior space of a vertical wall t, 5 or t or into the interior of the base 2 when this is ,of hollow construction. The flow pipe (also not shown) is connected at the upper end of the rear wall 4 or at the top of the boiler and the outlet for the products of combustion from the chamber 3 is constituted by an aperture 1 formed in the rear wall t adjacentto the underside of the top 3. The preferred arrangement shown has the front of the boiler constituted by the edges of the base asides 5 and t and top 3, the rectangu-' or mica, in a suitable frame and a rear wall constituted by a grating I la with which co-operates a slidable grating lib to form a hit-andmiss shutter device which may be closed to protect the glass or the like. Mounted'upon the inclined top 3 of the boiler is a fuel hopper I3 having vertical side walls and a vertical front wall lite and i319, respectively, but an upwardly inclined bottom 30. The inclination of the bottom iiic is the same as that of the boilertop 3 so that the hopper it fits closely to the latter, being held against forward movement by upstanding lugs or ears 12 secured on the lower edge of the top 3. The hopper, which may have retaining flanges at the lower edges of its sides 53a, has internal inclined plates Ht arranged near its lower extremity to guide fuel to a central discharge orifice l5 formed in its bottom and adapted to register with an opening l6 formed in the boiler-top 3. This opening It (see Fig. 2) has its wall continued as an inclined pipe H which ter-' minates vertically above the centre of the boilerbase 2, 2a. Ihe pipe il may have an adjustable lower end portion lla telescopically engaged therein and held by a clamping bolt it or the like. Beneath the end of the pipe there is mounted over the base 2, 2a of the boiler a domed fuel supporting member i9. ihe member I9 is hollow, with a domed base lila, and is spaced somewhat from an apertured plate 25), supported from the boiler-base, but is attached thereto by welding at'its loweredge at spaced points so that air outlet slots N are provided between the said lower edge of the member and the said plate directed towards the back 4 and sides 5, ii of the fire-box. The fuel-supporting member it has attached an upwardly inclined water-conveying pipe 22 which connects the interior space of the fuel-supporting member to the interior space of I the rear wall i of the boiler and an almost horizontal pipe 23 which connects the saidinterior spaces near the bottom 2, 2a of the boiler.v In

larger boilers having a base formed with waterways the pipe 23 may be connected into the latter. An air pipe 24 opening through the member i9 into thespace beneath'it is continued upwardly in close association with the inclined water-conveying pipe 22 (it may be welded or brazedthereto or integral therewith) for a short distance to terminate in a vertical portion on which is mounted a horseshoe-shaped pipe 25 beneath the apertured platel2il and a pipe 28' leading to the outlet of a blower or fan 29 is connected to the aperture in the plate Zil, passing through the boiler-base The preferred ar rangement has the boiler mounted on short legs 3t and the'fan 29 with its electric motor is located beneath and somewhat to the rear of the boiler. The motor is controlled by a thermostat (not shown) which is preferablyof the immersion type and located either in the flow pipe of the system or in an aperture in a side wall (5 or B) of the boiler closely adjacent to the upper end of the top 3. The pipe 28 leading to the blower 29 preferably extends vertically downwards to an elbow bend from which it then extends either to one side of the boiler or (as shown) rearwardly, a light flap valve 3! being pivotally hung from the upper edge of an opening 32 (Fig. 2) in the vertical part of the pipe and surrounded by a suitable seating 33 so that when the fan or blower is operative the valve '3! is held on to the seating 33 and prevents escape of air from the pipe 28. On the other hand, when the fan 29 is inoperative the natural draught through the fire-box causes the valve 3! to move inwardly from its seating 33 to allow air to pass to the interior of the pipe 23 and thence to the fuel bed, the lower edge of the valve 3| having small projections at each end on its inner face to space the latter from the opening 32 while the valve is thus inwardly displaced. Additional air may be supplied for some fuels through slots or apertures formed in the door 9, suitable controlling means being provided as will be understood.

Inorder to provide "for the supply of gaseous fuel, as when it is desired to :operate the boiler for short periods, without lighting a fire therein each time, a vertical pipe 34 (Fig. .2) is provided to extend through the wall of the elbow bend in the pipe 28 and terminate just beneath the fuel-supporting member l9, 19a, its outer A sliding blade shut-off member 36 is provided for closing the outlet from the hopper 13 during clinkering operations but this member may be replaced by a part-cylindrical blade working in a forwardly projecting enlargement of the front wall of the hopper on a horizontal spindle controlled by an external handle. The leading edge of the blade 36 may be formed with prongs or fingers to facilitate its penetration through the fuel or the blade may be replaced by a set of curved prongs or fingers. The upper end of the hopper I3 is provided with a hinged door Si in the example illustrated but may be formed to receive a sheet metal cover which may however be replaced by a rectangular extension of the hopper when the capacity thereof is to be increased, the cover then fitting the mouth of the extension. After the shut-off member 33 has been operated to the closed position, the hopper i 3 may readily be lifted over the retaining lugs or ears i2 and removed for filling purposes.

The operation of the boiler will be understood from the foregoing description, the fuel descending from the hopper l3 on to the supporting member {6 to form a bed 38 (Fig. 2) of the required thickness to which air is supplied from beneath through the outlet slot 2! at the edge of the member. Secondary air is supplied above the fuel bed 38 by way of the horseshoe-shaped pipe 25. It will be appreciated that the total area of the water-walls of the combustion chamber I is considerably greater than is the case in boilers of ordinary construction and it is, in fact, found that a boiler in accordance with the invention need be only half the size of any existing boiler of the same rating.

A further advantage, which results from the use of the adjustable fuel-pipe I1, Ha is that the size of the firebed 38 may be adjusted to suit requirements. For example, the boiler may be installed to supply a system of a predetermined size and the system may subsequently be enlarged by the introduction of a further radiator or radiators, another bath or the like. By means of the adjustable pipe ll, l'ia the size of the fire, initially adjusted to be adequate for the system, may be increased so that the boiler will satisfactorily serve for the enlarged system.

It is preferred to arrange for the combustion products leaving the fire-box I to travel for as long as possible in contact with the rear face of the rear wall 4 of the boiler. To this end, the outlet aperture 1 near the top of the rear wall t delivers into the upper end of a vertical flue 39 comprised between the said wall and a further wall 56 disposed parallel and co-extensive therewith. The space between these walls 4 and All (closed around the edges as will be understood) is subdivided into three flues by a pair of partitions ii joining the walls; a central flue 39 into which the outlet 1 from the fire-box or combustion chamber l delivers and two outer flues 42 (Fig. 3) communicating with the central flue 3? at their lower ends and discharging at their upper ends to a common outlet 43 leading to a chimney or the like. An ash collecting tray A l may in some cases constitute the closure for the lower end of the flue space just described and be supported on a horizontal ledge 22) having an opening or openings 20 through which flue-cleaning implements may be introduced after removal of the ash-tray 44.

One of the outer side walls of the subdivided flue space may, as shown, have an aperture 45 therein, normally closed by a cover late 46, over which aperture may be fitted a cooking oven 41 (shown in place in Fig. 1) having a flue space 48 through which hot gases are intended to circulate. A bafile plate 49 (Fig. 1) is suitably disposed in the oven flue-space 48 to ensure that the hot gases flowing through the flue of the boiler will be diverted through the oven fines and eventually return into the boiler flue. The oven may be mounted in any suitable manner on the boiler, preferably on one of the side walls thereof.

What I claim is:

1. A water-heating boiler for domestic and central-heating purposes comprising a bottom with side, front and rear edges and forming the lower boundary of a combustion chamber, a front wall of small height at the front edge of the bottom, a hollow rear wall of greater height than said front wall at the rear edge of the bottom, hollow sidewalls at the side edges of the bottom each increasing progressively in height from the front, where its height equals that of the front wall, to the rear, where its height equals that of the rear wall, a hollow rearwardly and upwardly inclined top wall connecting the upper edges of the side walls and the rear wall, passages affording free communication between the hollow spaces of the said rear, side and top walls,

which spaces are adapted to be filled with water, an aperture in the bottom, means for supplying air through said aperture into the combustion chamber, a hollow fuel-supporting member disposed within the said chamber closely above the said aperture, waterways connecting the hollow space of the fuel-supporting member to the hollow spaces of the said walls, a through aperture in the inclined top wall adjacent to the front wall, a fuel tube extending inwardly of the combustion chamber from the aperture in the top wall to terminate above the fuel-supporting member, a hopper for solid fuel having an upwardly and rearwardly inclined bottom wall that is adapted to seat upon the correspondingly inclined top wall, and an outlet from the said hopper adapted to register with the aperture in the said top wall when the hopper is seated on the latter.

2. A boiler as claimed in claim 1, in which the fuel-supporting member is formed with an outlet passage for conducting air from beneath the member to means for delivering air above the said member.

3. A boiler as claimed in claim 1, in which the fuel-supporting member is formed with a through aperture opening to the space beneath the side member, an air passage is intimately associated with one of the water-ways leading from the said member to have an end connected into the said through aperture therein, and. means is provided at the other end of the air passage to deliver air therefrom above a bed of fuel supported on the said member.

4. A boiler as claimed in claim 1, in which an outlet for combustion products is arranged in the rear wall near the upper end of the inclined top wall and a flue system is provided in contact with the outer face of the said rear wall to conduct the combustion products from the said outlet to a discharge point.

5. A boiler as claimed in claim 1, in which a flue system is provided in contact with the outer face of the rear wall comprising a vertical flue passage having an inlet at its upper end, at least one other vertical flue passage having an outlet at its upper end, the lower ends of the said passages being in communication with each-other, a connection totheinlet of the firstmentioned fiue passage from the combustion chamber oi the boiler, and a connection from the outlet. of the second-mentioned flue passage to a main discharge flue.

6.- A boiler as claimed in claim 1, in which the means for supplying air through the aperture. in the bottom of the combustion chamber comprises a conduit leading from a blower, an

8 opening tothe atmosphere in the said conduit anda light flap valveco-operating with the said opening to seal the latter automatically while the blower is operative but otherwise permitting air to enter the conduit from the atmosphere. 7. A boiler as claimed in claim 1, including means for supplying towns gas beneath the fuelsupporting member.

JOSIAH WATTS; 

